Cylinder lock



Dec.22,;1970 C. RQSSETT. 3,548,62fl

CYLINDER LOCK Filed July 3, 1968 fiql L1 T PRIOR ART 3 1 United StatesPatent CYLINDER LOCK Charles Rossetti, Avenue du Servan 24, Lausanne,Switzerland Filed July 3, 1968, Ser. No. 742,414 Claims priority,application Switzerland, July 7, 1967,

Int. Cl. Eb 9/08 US. Cl. 70-370 2 Claims ABSTRACT OF THE DISCLOSURE Acylinder lock comprising a casing having a bore to receive a rotatablecylinder. An entry part of the bore and an end part of the cylinder havecomplementary conical bearing surfaces and the cylinder is locatedaxially in the casing by a resilient ring engaged in facing groovesformed in bearing surfaces. The lock is assembled by threading the ringonto the cylinder then pushing the cylinder, into the bore to expand orcontract the ring so that it can enter the grooves, the resiliency ofthe ring thereafter holding the lock together.

The present invention relates to cylinder locks.

Known locks comprise a cylinder or barrel rotating in a bore in a lockcasing and carrying a plurality of locking elements in the form of pinsor the like adapted to engage in corresponding recesses in the bore inthe casing. If the locking members carried by the cylinder are to be inalignment with the corresponding recesses in the casing, the cylindermust be accurately located axially in the bore.

In known locks of this kind the cylinder has at one end a bearingsurface of enlarged diameter, which abuts the lock casing and is formedat its other end with a groove receiving a resilient ring or clip whichabuts the opposite end of the lock casing.

This arrangement has a number of disadvantages. The lock casing must bemanufactured accurately to length, as must the corresponding cylinderpart between the enlarged-diameter bearing surface and theclip-receiving groove. The recesses in the cylinder and in the casingfor the locking elements must also be accurately positioned relativelyto the end faces of the pins, and such end faces are readily distorted.The resulting close rnachining tolerances make manufacture complex andcostly. Also, the resilient ring is disposed outside the casing and isreadily accessible, and so the cylinder can be removed by unauthorizedpeople who may not always be able to provide a satisfactoryreassembling.

It is an object of the invention to provide a lock which is of greatlysimplified manufacture and which has the further advantage of preventingany disassembling of the cylinder.

It is yet another object of the present invention to provide a cylinderlock comprising a cylinder rotatably mounted in a bore in a lock casing,the cylinder being located axially in the casing by a resilient ringwhich is received in co-operating facing grooves in the casing and thecylinder.

With these and other objects in view which will become apparent in thefollowing detailed description, the present invention will be clearlyunderstood in connection with the accompanying drawing, in which:

FIG. 1 is a fragmentary elevational view of a known lock;

FIG. 2 is a view similar to that of FIG. 1 of a lock according to thepresent invention;

FIG. 3 is an enlarged fragmentary view showing some details of the lockshown in FIG. 2;

FIGS. 4 and 5 are views similar to that of FIG. 3

ice

showing the phases of assembling the cylinder in the lock casing;

FIGS. 6, 6a, 7 and 7a are diagrammatic views showing phases in themanufacture of the lock cylinder and casing, and

FIG. 8 is a fragmentary view of another embodiment of the presentinvention.

In the known lock shown in FIG. 1, a cylinder 1 rotates in a bore 2 of alock casing 3. For axial location of the cylinder 1 in the bore 2. Thecylinder 1 has at its left-hand end a head 4 which is of larger diameterthan the rest of the cylinder 1 and which abuts the casing 3, while atits right-hand end the cylinder 1 is formed with a groove 5 receiving aresilient ring 6 abutting the opposite end of the casing 3.

The axial play of the cylinder in the casing (which play is necessary ifthe cylinder 1 is to rotate satisfactorily) is shown to an exaggeratedscale by the reference T and depends upon the accuracy of threedimensions, namely the length L1 of the cylinder 1, the length L2 of thecasing 3 and the axial width E of the ring. The bearing surfaces and endfaces determining the lengths L1, L2 and machined by different tools,and so the manufacture of these items to close tolerances requires theuse of accurate machines with careful setting-up and many inspections.

In the lock according to the invention, shown in FIG. 2, a cylinder 11rotatable in a bore 12 of a lock casing 13 is located axially therein bya resilient ring 14 received in cooperating facing grooves 15 and 16 inthe casing 13 and cylinder 11 respectively (FIG. 3). The two grooves 15and 16 have, with allowance for a very slight clearance, the same axialwidth B as the resilient ring 14. The grooves 15 and 16 and the ring 14are all rectangular in cross-section.

Each of the two grooves 15 and 16 can be machined by means of a cuttingtool which forms the two opposite side surfaces of the groovesimultaneously, with the result that the groove has the same axial widthas the tool. Grooves of exactly the required width can therefore bereadily made, with the result that the cylinder engages axially in thecasing without excessive axial play, although no costly tooling isinvolved.

As can be seen in FIG. 3, the grooves 15 and 16 are disposed at the baseof matching frustoconical bearing surfaces 17 and 18 of the bore and ofthe cylinder.

As FIG. 4 shows, the maximum diameter D of the bearing surface 17 whichforms a frustoconical entry part of the bore is slightly larger than theouter diameter D1 of the resilient ring 14 when the same is in anunstressed state. The inner diameter d1 of the ring 14 is approximatelyequal to the diameter of the cylinder, and so the ring 14 can readily bethreaded thereon.

When the cylinder with the ring on it is introduced into the bore, thering extends into the conical entry part 17, to be compressed thereby toa smaller diameter in proportion as the cylinder is advanced through thebore. After having passed over the conical part 17 (FIG. 5), thetemporarily compressed ring 14 drops into groove 15 and, because of itsresilience, expands into the groove 15. However, the diameter D2 of thebottom of the groove 15 is smaller than the external diameter D of thering when the same is in its unstressed condition so that the radiallyinner part of the ring stays engaged in the groove 16. The cylinder istherefore retained in the lock casing by the now inaccessible resilientring 14.

In the embodiment shown in FIG. 8, a resilient ring 21 which isapproximately square in cross section is first placed in a groove 22 ina conical entry 23 of a lock casing bore. A cylinder 24 is thenintroduced into the ring 21, then pushed into the bore in the casing sothat a conical part 25 of cylinder 24 opens the ring 21, the latterengaging in a groove 26 in the cylinder so as to locate the sameaxially. In this embodiment the major diameter D3 of the matchingcomplementary parts is greater than the external diameter of the ringwhen the same is in its unstressed condition, and the minor diameter d3of the conical parts is smaller than the internal diameter of the ringwhen the same is in its unstressed condition to facilitate introductionof the ring into the casing and of the cylinder into the ring.

FIGS. 6 and 6a are diagrammatic views showing how the lock is made usingcutting tools 30 and 31 to turn the grooves 15 and 16 in the casing 13and cylinder 11. Apart from tool Width, which must be accurate, noaccuracy is required in these operations and the axial position of thegrooves can readily vary within wide tolerances.

The apertures for receiving the locking pins are drilled subsequently inthe manner shown diagrammatically in FIGS. 7 and 7a. The casing 13 andthe cylinder 11 are disposed on drilling jigs having projections N whichengage in the previously formed grooves 15 or 16. Consequently, theholes drilled via apertures 34 in the drilling jigs are accuratelylocated axially relatively to the grooves 15 and 16 which are disposedfacing one another in the assembled lock.

Axial location of the cylinder is therefore the result of very simplesteps, and the grooves can be machined independently of article length,which may vary. The same drilling jigs can therefore be used tomanufacture cylinders of various lengths.

The resilient ring is e.g. a steel ring split radially by a saw cut.Alternatively, the resilient ring can be a loop of spring wire or anyother element adapted to engage simultaneously in the two facinggrooves.

In a variant, the cylinder can be formed with slots for I claim:

1. A cylinder lock comprising a lock casing having a bore therein and aplurality of radial holes,

a cylinder rotatably mounted in said bore,

a plurality of cylindrical locking pins carried by said cylinder andengaged in corresponding of said radial holes in said bore when saidcylinder is in a locked position, said locking pins and radial holeshaving the sam diameters,

said casing 'nd said cylinder having cooperating facing grooves, and

a resilient ring received in said cooperating facing grooves, saidresilient ring being of the same axial width as that of said facinggrooves and exclusively locating said cylinder in said bore in anaccurate axial position, so that said locking pins are properlypositioned in said corresponding radial holes in said bore,

said bore of said casing and said cylinder defining complementaryfrustoconical surfaces, and

said cooperating facing grooves being in said frustoconical surfaces.

2. The cylinder lock, as set forth in claim 1, wherein said metallicresilient ring is massive and its outer diameter and inner diameter inthe unstressed state thereof are smaller and larger, respectively, thanthe largest and smallest diameters, respectively, of said frustoconicalsurfaces.

References Cited UNITED STATES PATENTS 1,741,093 12/1929 Briggs 703671,772,747 8/ 1930 Croning 70-252 2,020,260 11/1935 Larsson 70-3702,111,511 3/1938 Lowe et al. 70221 2,761,111 8/1956 Klostermann 339923,316,742 5/ 1967 Wellekens 70-379 MARVIN A. CHAMPION, Primary ExaminerR. L. WOLFE, Assistant Examiner US. Cl. X.R. 70 3s1, 451

